This is a contract for the support of field activities related to various research projects being conducted within DIR's Epidemiology Branch. Currently, no studies have been assigned to this contract; CODA, Inc., coordinates all of the data collection activities for studies. This work includes questionnaire development, telephone and personal interviewing, specimen collection, data editing and computerization. Computer expertise (e.g., programming and biostatistical support) is provided by Westat, Inc. as a subcontractor to CODA, Inc.